This application is based upon and claims the benefit of priority from the prior Japanese Patent Applications No. 2002-118137, filed Apr. 19, 2002; and No. 2002-126328, filed Apr. 26, 2002, the entire contents of both of which are incorporated herein by reference.
1. Field of the Invention
The present invention relates to a liquid crystal display.
2. Description of the Related Art
A liquid crystal display, which is thin, light in weight and low in power consumption, is used is various fields such as OA equipment, an information terminal, a watch and a television receiver. Particularly, a liquid crystal display equipped with a thin film transistor (TFT) exhibits a high response capability and, thus, is used as a monitor of an apparatus that displays a large amount of information, such as a portable television receiver or a portable computer.
In recent years, demands for a picture image of high definition and short response time are being increased, in parallel with the increase amount of information. Of the above, high definition images are accomplished by, for example, miniaturization of the array structure forming the TFT.
On the other hand, concerning the demand for the shortening of the response time, it is being studied to employ the display mode using a nematic liquid crystal, such as an IPS mode, an HAN mode, an OCB mode, a xcfx80-mode and a multi domain-type VAN (Vertical Aligned Nematic) mode, or the display mode using a smectic liquid crystal, such as a surface stabilized ferroelectric liquid crystal mode and an antiferroelectric liquid crystal mode, in place of the conventional display mode.
Among these display modes, the multi domain-type VAN mode permits obtaining a response speed higher than that in the conventional TN (Twisted Nematic) mode. Also, a rubbing treatment that generates undesired phenomena such as an electrostatic destroy is not required in the multi domain-type VAN mode because the liquid crystal molecules are oriented in the vertical direction in the multi domain-type VAN mode. Further, the design for the compensation of the viewing angle can be achieved relatively easily in the multi domain-type VAN mode.
However, the viewing angle for the multi domain-type VAN mode is smaller than that for the IPS mode. Naturally, it is desirable to further broaden the viewing angle in the multi domain-type VAN mode.
According to a first aspect of the present invention, there is provided a liquid crystal display, comprising an array substrate with first to third pixel electrodes on a main surface thereof, a counter substrate with a common electrode that faces the first to third pixel electrodes on a main surface thereof, a liquid crystal layer sandwiched between the array and counter substrates, and a color filter supported by one of the array and counter substrates and comprising first to third coloring layer facing the first to third pixel electrodes, respectively, wherein the display is configured to form first and second optical regions different from each other in electric field intensity in each of first to third pixel regions between the common electrode and the first to third pixel electrodes when voltage is applied therebetween, the first and second optical regions extending in a direction that is parallel to the liquid crystal layer and alternately arranged in a direction that crosses a longitudinal direction of the first optical region in each of the first to third pixel regions, and the first pixel region being different in the longitudinal direction of the first optical region from the second and third pixel regions.
According to a second aspect of the present invention, there is provided a liquid crystal display, comprising an array substrate with first to third pixel electrodes on a main surface thereof, a counter substrate with a common electrode that faces the first to third pixel electrodes on a main surface thereof, a liquid crystal layer sandwiched between the array and counter substrates, and a color filter supported by one of the array and counter substrates and comprising first to third coloring layer facing the first to third pixel electrodes, respectively, wherein the display is configured to form first and second optical regions different from each other in electric field intensity in each of first to third pixel regions between the common electrode and the first to third pixel electrodes when voltage is applied therebetween, the first and second optical regions extending in a direction that is parallel to the liquid crystal layer and alternately arranged in a direction that crosses a longitudinal direction of the first optical region in each of the first to third pixel regions, and wherein the first pixel region is different in a shape of the first and/or second optical region from the second and third pixel regions.
According to a third aspect of the present invention, there is provided a liquid crystal display, comprising an array substrate with first to third comb-shaped electrodes on a main surface thereof, a counter substrate with a common electrode that faces the first to third comb-shaped electrodes on a main surface thereof, a liquid crystal layer sandwiched between the array and counter substrates, and a color filter supported by one of the array and counter substrates and comprising first to third coloring layer facing the first to third comb-shaped electrodes, respectively, wherein the first comb-shaped electrode is different in shape and/or orientation from the second and third comb-shaped electrodes.
Where voltage is applied between the pixel electrode and the common electrode under the state that polarizers are arranged on the sides of the light source and the observer, the first optical region and the second optical region can be observed as regions differing from each other in the transmittance or the reflectance. In other words, the first and second optical regions can be confirmed by actually measuring the intensity of the electric field and/or by examining the transmittance or the reflectance.
It is not absolutely necessary for a clear boundary to be present between the first optical region and the second optical region. In other words, it is possible for the intensity of the electric field and the magnitudes of the transmittance or the reflectance to be changed continuously in the arranging direction of the first optical region and the second optical region.
Where a clear boundary is not formed between the first optical region and the second optical region, the sum of the width of the first optical region and the width of the second optical region is scarcely dependent on a boundary value, which is a value defining the boundary between the first and the second optical regions. However, the individual widths of the first and second optical regions are dependent on the boundary value. It follows that, where it is necessary to obtain the boundary between the first optical region and the second optical region, an appropriate value such as an average value of the electric field intensity, the transmittance or the reflectance can be used as the boundary value.